No reception channels 4 and 5 NE of Seattle
 

We're trying to cut the cable and have installed a Channel Master CM-4228 HD antenna with the CM-7778 preamp. The installation a 5' mast mounted to our chimney, about 30' off the ground. I ran new RG-6 cabling and ran a channel auto scan on a television with perhaps a total 40' cable run. We live in a fairly densely wooded area on Wagner Hill, just north of Monroe WA.

Here is the TV Fool radar plot for us:

http://www.tvfool.com/?option=com_wr...5b94c520f44054

The antenna is aimed at 216 degrees magnetic.

Here's what we're receiving:
KOMO-4 no signal
KING 5.1 - none
KING 5.2 - no signal
KIRO 7.1 and 7.2 - perfect
KCTS 9.1 - perfect
9.2 and 9.3 also good
KSTW 11.1 - perfect
KCPQ 13.1 - perfect
KZJO 22.1 - perfect
Also 22.2 and 22.3 all good

All this to say, we're very pleased with the exception of channels 4 and 5.

Any ideas why channel 7 is fine while the relatively co-located 4 and 5 are not and what we can do to receive 4 and 5?

Thanks so much for any help and advice.

Only a few antennas will offer marginally better UHF performance, not enough to suggest you start by replacing the 4228...

Have you experimented with other antenna locations? In some cases, a move of inches can make a significant difference. Be willing to try any reasonably safe location...

+=>
-----
The Tvfool radar report and channel list shows the Real Channel that is being transmitted and received.

The Current Tv channels that are being transmitted and received in the , USA , Canada , Mexico , are.

VHF low band channels 2 thru 6.

VHF high band channels 7 thru 13.

UHF band channels 14 thru 51.

--------------------------

KOMO is Real UHF Channel 38.

KING is Real UHF channel 48.

The UHF channel frequencies are short wave length and tend to be very directional and at a reception location this can create , Dead spots where the signal is low signal strength.

Moving the antenna up or down can move the antenna out of a dead spot.

And changing the aim of the antenna can also help with reception.

Trees and tree leaves , reflect (multi-path) , absorb , block , Tv reception , and some channels can be more effected then others.

Moving the antenna to a location that has less to no trees in the direction of reception will help with reception.

Most Digital Tv's have a Signal Strength Meter and some Digital Tv' also have a Signal Quality Meter.

Signal Quality is important reliable reception.

If the Tv has a Signal Quality Meter , adjust and aim and locate the antenna for best signal quality.

------------------

Also , Digital Tuners can develop -Digital Glitches- that are not cleared out with simple channel scans.

To clear tuner do Double Rescan.

http://www.wchstv.com/DoubleReScanAlert.pdf.

Thanks!
 

Thanks for the quick replies - appreciate all the advice.

Great quote - we are so ready to run out and buy a better pump when we need to dig a deeper well! I was already looking at different antennas. That said, just ordered two more sections for antenna mast and will begin experimenting.

Ran the double scan. No luck but we'll see with various heights and directions.

Amazingly fast and knowledgeable help; it is much appreciated!